JP3420467B2 - Rocker arm manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rocker arm used for an engine valve mechanism.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a rocker arm, a plurality of vertical press machines are used, and a blank of a predetermined shape is stepwise pressed into a rocker arm shape by these press machines. It has been known.

By the way, the rocker arm has a flat and elongated shape having concavities and convexities, etc., and its shape is very complicated. Therefore, the friction coefficient during press working is large and the workability is poor. It was a thing. Therefore, when the blank is directly subjected to forging by using a single-stage pressing machine or a multi-stage forging machine as disclosed in Japanese Utility Model Laid-Open No. 5-9734, under cold conditions, It was difficult to mold it into a predetermined shape, and cracks were also generated, making it difficult to obtain a desired rocker arm. Further, if the heated blank is directly subjected to press working under heat, the workability becomes good, and even a complicated shape can be easily formed.
On the other hand, since it is hot working, a dimensional error occurs due to cooling, so it is difficult to obtain a high-precision rocker arm.Therefore, it is necessary to specially perform dimensioning processing for the entire molded product as a post-treatment after molding. It was

Therefore, in recent years, a lubricating liquid is adhered to the surface of the blank to form a lubricating coating layer for lowering the coefficient of friction during press working to improve workability and to suppress the occurrence of cracks. , By supplying the blank on which this coating layer is formed to a plurality of single-stage press machines, and by stepwise pressing under cold conditions in each press machine,
We are trying to obtain a high-precision rocker arm that does not crack.

[0005]

By the way, according to the method for manufacturing a rocker arm using the above-mentioned blank on which the lubricating coating layer is formed, a blank forming step of forming a metal blank in a predetermined shape in advance, and the blank. Requires a lubricating film forming step of forming a lubricating film layer on the surface of, and a supplying step of supplying the blank on which the lubricating film layer is formed to the press machine. Then, these respective steps are independent of each other and are independent of each other, and therefore supply of the blank formed in the first blank forming step to the lubricating film forming step is very complicated and time-consuming, and As for the supply from the lubricating film forming step to the press, it was very troublesome and could not be smoothly supplied, resulting in a problem that the workability was very poor.

Therefore, an object of the present invention is to use a metal wire material having a lubricating coating layer formed on the outer peripheral surface thereof to manufacture a rocker arm with high precision without cracking by a cold press forming machine, and further, in its work. An object of the present invention is to provide a method for manufacturing a rocker arm that can improve the property.

Another object of the present invention is to provide a method for manufacturing a rocker arm which enables the rocker arm to be press-formed at high speed and at the same time suppresses the enlargement of the press-forming machine.

Still another object of the present invention is to make each cross-section of a metal wire material having a lubricating coating layer formed on its outer peripheral surface into a rectangular cross-section close to the cross-sectional shape of the rocker arm to be manufactured. It is an object of the present invention to provide a method of manufacturing a rocker arm that can further improve workability in a station.

[0009]

In order to solve the above problems, the present invention is characterized by having the following configuration.

That is, the invention of claim 1 of the present application (hereinafter,
The first invention) is a method of manufacturing a rocker arm having a flat shape and a relatively elongated shape as a whole, and uses a metal wire material, and lubricates the outer peripheral surface of the material to reduce the friction coefficient during forging. Liquid is applied to form a lubricating coating layer,
Then, the material is supplied to the vicinity of the upper forging station in the cold forging machine, which is formed by arranging a plurality of forging stations each including a movable die and a fixed die,
The material is cut to a predetermined size at the supply position, and after that,
The cut blank is supplied to the forging station so that the surface on which the lubricating coating is formed faces the forging surfaces of the movable die and the fixed die in the upper forging station, respectively, and then the blank is fed to the forging station. The intermediate formed product formed by forging is sequentially transferred to each forging station on the lower stage side so that the lubricating film forming surface faces each forging surface of the movable mold and the fixed mold in each forging station on the latter stage side, It is characterized in that the press forming is performed stepwise into rocker arm shapes at these press forming stations.

Further, the invention of claim 2 (hereinafter referred to as the second invention) is the manufacturing method of the first invention, in which a plurality of stages of forging stations are arranged horizontally so that each movable mold moves on a horizontal plane. Using a cold forging machine that is installed, the metal wire material is fed near the forging station in the upper stage in a horizontal direction and in a direction orthogonal to the arranging direction of the forging stations, and the material is fed at the feeding position. By rotating the longitudinal direction of the blank cut into a predetermined size by 90 degrees so as to be orthogonal to the material supply direction, the lubricating film formation surface of the blank is moved to the movable die and the fixed die in the upper forging station. It is characterized in that it is made to face the forging surface, respectively.

The invention of claim 3 (hereinafter referred to as the third invention) is a method of manufacturing the first invention or the second invention, wherein the metal wire material has a cross section orthogonal to the longitudinal direction of the rocker arm to be manufactured. A blank formed by using a metal wire raw material having a rectangular cross section similar to the shape and cutting the raw material to a predetermined size is used in a forging station in which one of the outer peripheral surfaces of the blank has a lubricating film forming surface facing each other in the upper stage. It is characterized in that it is supplied so as to face the respective forging surfaces of the movable die and the fixed die.

According to such a manufacturing method, the following effects can be obtained.

First, according to the first aspect of the invention, a metal wire material having a lubricating coating layer formed on the outer peripheral surface thereof is used, and the metal wire material is supplied near the forging station in the upper stage of the cold forging machine.
At the supply position, the material is cut into a predetermined size, and the cut blank is placed in the upper stage so that the lubricating film forming surface faces the forging surfaces of the movable die and the fixed die at each forging station. Supply to the forging station. Then, the intermediate molded product that has been forged at this forging station is sequentially transferred to each forging station on the subsequent stage, and at each forging station, forging is further stepwise formed into a rocker arm shape to manufacture a rocker arm. Become. As a result, using a metal wire material having a lubricating coating layer formed on the outer peripheral surface thereof, a blank obtained by cutting the material into a predetermined size is cooled so that the lubricating coating forming surface faces each of the forging surfaces. It becomes possible to continuously supply to the interhead forming machine. Further, in each forging station, since the lubrication film forming surface of the blank faces the forging surface of the forging station and the forging surface of the fixed die respectively, forging is performed, so that the moving die of each stage is It is possible to reduce the coefficient of friction when molding with the fixed mold, which improves workability even under cold conditions and improves the product with a predetermined shape without cracking. It is possible to perform press forming with accuracy.

According to the second aspect of the invention, a cold forging machine having a plurality of forging stations horizontally arranged in parallel is used, and an outer peripheral surface is provided near the upper forging station of the forging machine. The metal wire raw material on which the lubricating coating layer is formed is supplied horizontally so as to be orthogonal to the direction in which the forging stations are arranged in parallel. After that, the material is cut into a predetermined size at the supply position, and a blank obtained by cutting the material into a predetermined size is rotated 90 degrees so as to be orthogonal to the material supply direction, and the blank is coated with the lubricating coating. The forming surface is supplied to the upper forging station such that the forming surface faces the movable and fixed forging surfaces of the upper forging station, respectively. In that case, in a multi-stage horizontal cold heading machine, the structure is such that each movable die is moved on a horizontal plane. It is possible to reduce the load burden on the drive system for horizontally reciprocating the movable die, which allows the movable die to reciprocate horizontally at high speed to quickly perform forging at each forging station. It will be possible.

Further, according to the third invention, as the metal wire material, a metal wire material having a rectangular cross section which is similar to the shape of the cross section of the rocker arm to be manufactured orthogonal to its longitudinal direction is used. A blank formed by cutting to a predetermined size is placed on the outer peripheral surface of the forging station in such a state that the opposing lubricating film forming surfaces on one side face the forging surfaces of the movable die and the fixed die in the upper die forging station, respectively. Since the press forming is performed by pressing, it is possible to reduce the deformation amount of the blank during the press forming and reduce the load during forming.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 10 show a method of manufacturing a rocker arm according to the present embodiment, in which a rocker arm R having a generally flat shape and a relatively elongated shape is manufactured using a multi-stage horizontal cold heading machine. The change of the shape of the forming material in the forming process in the case is shown.

First, in FIG. 1 and FIG. 2, reference numeral X'denotes a metal material X (see FIG. 11) having a rectangular cross section which is wound in a coil shape in advance in the lubricating film forming step, and is a lubricating liquid tank such as zinc phosphate. The metal wire blank X, which is dipped into the metal wire and has the lubricating coating H formed on its outer peripheral surface, is then cut into a predetermined length in a cutting step to show a rectangular-shaped blank. Here, the cross-sectional shape of the metal wire material X, that is, the blank X ′ is a rectangular cross-section that is similar to the cross-sectional shape of the rocker arm R to be manufactured, which is orthogonal to the longitudinal direction thereof.

Next, in FIGS. 3 and 4, reference numeral X1 indicates a product portion a and a thickness of the product portion a when blank X'is preformed at a first forging station by a horizontal cold forging machine described later. It is a primary molded product having a burr b on the outer periphery of the middle portion in the direction.

Reference numeral X2 in FIGS. 5 and 6 indicates that the burr b of the primary molded product X1 is punched out at the second forging station of the horizontal cold forging machine to form a through hole c in the center of the product portion a. It is a secondary molded product.

Further, in FIGS. 7 and 8, reference numeral X3 indicates a product portion a'where the secondary molded product X2 is formed for further accurate dimensioning at the third forging station of the horizontal cold forging machine. And a tertiary molded product having burrs b ', b "on the inner and outer circumferences of the intermediate portion in the thickness direction of the product portion a'.

Further, in FIG. 9 and FIG.
It is a rocker arm as a final molded product in which burrs b ', b "of the tertiary molded product X3 are punched out at the fourth forging station of the horizontal cold forging machine and a through hole c'is formed in the central portion.

Although not shown, the final molded product R may be subjected to cutting or the like as necessary after the press forming of a shaft hole portion or the like which cannot be formed by the horizontal cold press forming machine. become.

Next, referring to FIGS. 11 and 12, a schematic structure of a multi-stage horizontal cold forging machine 1 for forging the rocker arm R will be described.

The press molding machine 1 has a die block 3 fixed to a predetermined position of a machine base 2, and a plurality of fixed dies 4 to 7 are horizontally arranged at predetermined intervals on the die block 3. Are installed side by side. In addition, the fixed molds 4 to 7 are provided on the front surface of the ram 8 that advances and retracts toward the die block 3.
A plurality of movable dies 11 to 14 are horizontally arranged side by side via die holders 15 to 18 so as to face each other, and the fixed dies 4 to 7 and the movable dies 11 to 11 that face each other are fixed.
14, the first to fourth forging stations S1 to S4
Is configured.

On the upper surface side of the die block 3, as shown in FIGS. 13 to 15, the blank swivel feeding device 30 for swiveling the blank X'to the first forging station S1 by 90 degrees and feeding it. Pressing stations S1 to S
Material parallel transfer chuck device for parallel transfer of the first to third intermediate molded products X1 to X3 molded in No. 3 (not shown)
Are provided, and the blanks X ′ are sequentially transferred to the lower forging stations by these chuck devices, and are forged stepwise at the respective forging stations, so that the fourth forging station S4 is finally obtained.
Then, a rocker arm R as shown in FIGS. 9 and 10 is formed.

Specifically, in the forging machine 1, as shown in FIGS. 11 and 12, a metal wire material wound into a coil is formed by applying the above-described lubricating film forming treatment to the rear portion of the machine base 2. A rotation support member 21 that rotatably supports X is provided, and
Roller type material supply mechanism 2 for supplying the material X into the machine base 2
2 is provided, and the metal wire material X introduced by the material supply mechanism 22 is provided on one side of the die block 3
A material supply quill 23 is provided between the ram 8 and the ram 8. At the front end of the quill 23, a cutter 24 and a stopper 25 that regulates the amount of protrusion of the material X from the quill 23 are provided. The cutter 24 allows the material X to be inserted therethrough. 24 is reciprocally driven with a predetermined stroke in the direction in which the fixed mold is arranged in parallel through a crank mechanism (not shown) that is driven in synchronization with the ram 8 and sent out forward from the material supply quill 23. The material X is cut into a predetermined size.

A pusher pin 26 is provided adjacent to the material supply quill 23 so that the blank X ′ cut into a predetermined size by the cutter 24 is projected from the cutter 24. At the front position of the pusher pin 26, the protruding blank X ′ is gripped, and the raw material is first turned over by 90 ° and the first blanking station S1 is pressed.
A material swiveling and feeding device 30 for transferring the material to is provided.

As shown in FIGS. 13 to 15, this supply device 30 includes an inverted L-shaped support rod 31 and two parallel upper and lower portions extending in the same direction as the projecting direction for gripping the projecting blank X '. Fingers 32a and 32b. One end of each of the fingers 32a and 32b is vertically swingably supported by a pin at an intermediate portion in the vertical direction of the support rod 31 at predetermined intervals, and
The two abutment portions 31a and 31b provided on the support rod 31 respectively restrict the swinging from the substantially parallel state to the side closer to each other, and the spring 33 is interposed between the fingers 32a and 32b. Therefore, it is always urged to maintain the parallel state. This allows both fingers 32
The a and 32b are closed by the biasing force of the spring 33, so that the upper and lower surfaces of the blank X'are held. The upper end of the support rod 31 is parallel to and swingable to a chuck block 34 fixed to the machine base 2 via a pair of links 35 (only one is shown in the drawing). Of the segment bar 36 and the chuck bar 37 supported by the chuck bar 37, the chuck bar 37 is fixed to the lower end portion of a chuck shaft 39 rotatably provided via a bearing member 38. A gear 41 is provided on the upper end of the chuck shaft 39, and the gear 41 meshes with a segment gear 42 fixed to the segment bar 36.

As a result, when the segment bar 36 and the chuck bar 37 are simultaneously swung with respect to the chuck block 34 via the pair of links 35, both bars 36,
37 moves in parallel in the same direction, but at that time, since the inner segment bar 36 and the outer chuck bar 37 have a difference in rotation distance from the rotation center of the link 35, the movement amount of the chuck bar 37 is reduced. It becomes larger than the movement amount of the segment bar 36. As a result, the chuck shaft 39 reciprocally rotates by 90 degrees due to the meshing rotation of the gear 41 and the segment gear 42 during one reciprocating movement.
The fingers 32a and 32b are adapted to supply the blank X'to the first forging station S1 while rotating 90 degrees while holding the blank X '.

On the other hand, of the forging stations S1 to S4, the first forging station S1 has a fixed die 4 and a movable die 11, as shown in FIG. 16, and a rocker arm is provided on the fixed die 4 side. A fixed die main body 4a for molding the outer shape of one side surface of R and extrusion pins 4b, 4b which are internally inserted through the main body 4a are provided. This push pin 4b,
The pins 4b and 4b are provided on the rear end side of the fixed mold body 4a.
There is provided a knockout mechanism (not shown) that projects outwardly from the fixed mold 4 to discharge the primary molded product X1. Further, on the movable die 11 side, a movable die body 11a forming the outer shape of the other side surface of the rocker arm R, and the body 11a.
Extruding pins 11b, 11b are provided so that they can be penetrated through. An extruding mechanism (not shown) is provided on the rear end side of the extruding pins 11b, 11b to push the pins 11b, 11b outward from the movable mold body 11a to extrude the primary molded product X1 to the fixed mold 3 side. Has been. Further, the movable mold 1 is attached to the front end surface of the mold holder 15 which holds the movable mold 11.
At the time of driving 1 into the fixed die 4, the material turning and feeding device 3
0 finger 32a, 32b is inserted between FIG.
As shown in FIG. 5, a tapered opening member 15 forcibly opening both fingers 32a and 32b to move them to the retracted position.
a is fixed.

In FIG. 16, reference numerals 4c, 4c and 11c, 11c are push pins 4b, 4b and 11b, 1 respectively.
It is a return spring for returning 1b to the original position in the fixed mold body 4a and the movable mold body 11a with the backward movement of the knockout mechanism and the pushing mechanism.

Then, the material X'is press-fitted into the fixed mold 4 from the side surface side thereof by the movable mold 4, and the movable mold 11
With the fixed die 4, a primary molded product X1 having a product portion a having the outer shape of the rocker arm R and a burr b having a specific shape on the outer peripheral portion in the thickness direction of the product portion a is formed.

When forming the burr b, the movable mold 1 is used.
It is formed by providing a predetermined gap between the movable die 11 and the fixed die 4 when the 1 is press-fitted into the fixed die 4. In that case, the fixed mold 4 is provided with restricting portions 4d, 4d for restricting the movement of the burr b in the product length direction, and by the restricting portions 4d, 4d, as shown in FIG.
The width b of 1 is set to a fixed dimension to form a burr b which also serves as a chuck holding portion. Thereby, when the primary molded product X1 is transferred from the first forging station S1 to the second forging station S2 by the material parallel transfer chuck device, the burr b is produced by the chuck claws of the chuck device.
The chuck holding part is held and transferred.

Further, as shown in FIG. 17, the second station S2 has a concave fixed mold 5 having an inner peripheral edge portion having the same shape as the contour shape of the primary molded product X1 and the contour shape of the primary molded product X1. , A convex movable mold 12 capable of plunging into the fixed mold 5
And the burr b is punched out when the movable mold 12 is inserted into the fixed mold 5. And
A fixed punch 5a for punching is fixedly provided in the center of the fixed die 5, and the fixed punch 5a is used to fix the primary molded product X1.
The second molded product X2 having a through hole c penetrating from the one side surface to the other side surface of the primary molded product X1 is punched out by punching out the central part thereof.

In this case, a cylindrical extruding member 5b is slidably provided at the center of the fixed mold 5 so that the secondary molded product X2 can be discharged from the fixed mold 5 after molding. A knockout mechanism (not shown) for pushing the pushing member 5b outward from the fixed punch 5a is provided on the rear end side of the pushing member 5b. Further, the movable die 12 is formed with a through hole 12a and a discharge passage 12b for discharging the punching piece d punched by the fixed punch 5a.

In FIG. 17, reference numeral 5c is a return spring for returning the pushing member 5b to the original position in the fixed die 5 in accordance with the backward movement of the knockout mechanism, and reference numeral 5d is the movable die 12. Is a stripper for removing the burr b punched on the outer periphery of the.

When the secondary molded product X2 is transferred from the second forging station S2 to the third forging station S3 by the chuck device for parallel material transfer, both ends of the product part a in the lengthwise direction are chucked by the chuck claws of the chuck device. Parts will be retained.

The third forging station S3 is substantially the same as the first forging station S1 and has a fixed die 6 and a movable die 13 as shown in FIG. 18, and a rocker is provided on the fixed die 6 side. A fixed die main body 6a that forms the outer shape of one side surface of the arm R, and push-out pins 6b and 6b that are internally mounted in the main body 6a so as to be able to penetrate therethrough are provided. This extrusion pin 6
A knockout mechanism (not shown) on the rear end side of b, 6b for ejecting the pin 6b, 6b outward from the fixed mold body 6a to discharge the molded tertiary molded product X3 from the fixed mold 6.
Is provided. On the movable die 13 side, a movable die body 13a that forms the outer shape of the other side surface of the rocker arm R,
Extrusion pin 13b that is internally pierceable in the main body 13a,
13b and the push-out pin 13b,
An extruding mechanism (not shown) is provided on the rear end side of 13b to push the pins 13b, 13b outward from the movable mold body 13a to push out the tertiary molded product X3 to the fixed mold 6 side. In FIG. 18, reference numerals 6c, 6c and 13
Reference characters c, 13c are return springs for returning the push-out pins 6b, 6b and 13b, 13b into the fixed mold body 6a and the movable mold body 13a when the knockout mechanism and the push-out mechanism move backward.

Then, the secondary molded product X2 is press-fitted into the fixed die 6 by the movable die 13, and the movable die 13 and the fixed die 6 form the outer shape of the rocker arm R into the product portion a '.
A tertiary molded product X3 having burrs b ', b "of a specific shape is formed around the outer surface in the middle of the thickness direction and around the through hole c.

Further, when forming the burr b ', the fixed mold 6 is provided with restricting portions 6d, 6d for restricting the movement of the burr b'in the product length direction, and by the restricting portions 6d, 6d.
As shown in FIG. 7, the lateral width of the tertiary molded product X3 is set to a constant dimension to form a burr b'also serving as a chuck holding portion. As a result, when the tertiary molded product X3 is transferred from the third forging station S3 to the fourth forging station S4 by the material parallel transfer chuck device, the chuck holding portion of the burr b is held by the chuck claws of the chuck device. It is designed to be transferred.

The fourth forging station S4 has substantially the same structure as that of the second forging station S2, as shown in FIG.
As shown in FIG. 3, a concave fixed mold 7 having an inner peripheral edge portion having the same shape as the contour shape of the rocker arm R, and a convex movable mold having the same shape as the contour shape of the rocker arm R and capable of being inserted into the fixed mold 7 14 is provided, and the burr b ′ is punched out when the movable mold 14 is inserted into the fixed mold 7. A fixed punch 7a for punching is provided in the center of the fixed die 7, and the fixed punch 7a for punching is used to punch out a burr b ″ in the central portion of the tertiary molded product X3 to form the tertiary molded product X3. A rocker arm R as a final molded product having a through hole c ′ penetrating from one side surface to the other side surface is formed.

In this case, a cylindrical pushing member 7b is provided around the fixed punch 7a at the center of the fixed mold 7 so that the rocker arm R can be discharged from the fixed mold 7 after molding.
Is provided slidably, and a knockout mechanism (not shown) for pushing the pushing member 7b outward from the fixed die 7 is provided on the rear end side of the tubular pushing member 7b. Also,
The movable die 14 has a burr b ″ punched by the fixed pin 7a.
A through hole 14a and a discharge passage 14b for discharging the are formed.

In FIG. 19, reference numeral 7c is a return spring for returning the pushing member 7b to the original position in the fixed die 7 with the backward movement of the knockout mechanism, and reference numeral 7d is a movable die 14. Burr b ′ punched on the outer periphery of
Is a stripper for eliminating.

Next, the manufacturing process of the rocker arm R which is carried out by using the multistage horizontal cold heading and forming machine 1 as described above will be explained.

In advance, a metal wire material X having a rectangular cross section in a coil winding state is immersed in a lubricating liquid tank of zinc phosphate or the like in a lubricating film forming step to form a lubricating film H on its outer peripheral surface. The coil-wound metal wire material X that has been subjected to the lubricating film forming treatment is supported by the rotation support member 21 in the coil-wound state.

When manufacturing the rocker arm R,
One end of the material X is pulled out from the rotation support member 21, and the material X is sent to the tip end port of the material supply quill 23 by the material supply mechanism 22. The material X sent out from the tip opening of the material supply quill 23 is inserted into the cutter 24 and its size is determined by the stopper 25, and then the cutter 24 moves so as to cross the tip opening of the quill 23 and moves. Is cut to size.

The cut blank X'is transferred together with the cutter 24 just before the pusher pin 26,
The blank X'is pushed out of the cutter 24 by the forward movement of the pusher pin 26, and fingers 32a, 3 of the material swiveling and feeding device 30 extending in the same direction as the pushing direction.
It is pushed against the spring 33 between the 2b and held. After that, when the pusher pin 26 retracts to the original position and the chuck bar 37 moves to the lower side, the fingers 32a and 32b hold the blank X'while holding the blank X'90 as shown by the phantom line in FIG. Rotate the blank X ',
The outer peripheral surface is supplied to the first forging station S1 so that the opposed lubricating film forming surfaces on one side face the forging surfaces of the movable die 11 and the fixed die 4 in the first forging station S1, respectively.

Next, in the first forging station S1, the blank X'is pressed into the fixed die 4 by the movable die 11 as shown in FIG. 16, and the dimensions of the movable die 11 and the fixed die 4 are set. A primary molded product X1 having a slightly low precision product portion a and a burr b of a specific shape on the middle outer peripheral portion in the thickness direction of the product portion a is molded. In that case, the movable mold 11 and the fixed mold 4
Of the movable die 11 by the lubricating coating layer H facing each forging surface of
It is possible to reduce the coefficient of friction at the time of molding by the fixed mold 4 and the workability to improve the workability, and it is possible to mold well without cracks.

At the time of this molding, as shown in FIGS. 14 and 15, the taper-shaped opening member 15a provided on the mold holder 15 of the movable mold 11 penetrates between the fingers 32a and 32b, so that both fingers 32a and 32b. By pushing and opening up and down, both fingers 32a and 32b are moved to the retracted position away from the moving path of the movable die 11.

After the completion of molding, the opening member 15a is released from the protrusion as the movable die 11 moves backward, and the fingers 33a and 32b return from the retracted state to the parallel state by the spring 33 and the chuck bar is released. When the pusher pin 26 is moved to the upper side,
It is rotated and supplied while being rotated by 0 degree, and returns to the original position shown by the solid line in FIG. The push-out pins 11b, 1 are aligned with the timing at which the swirl supply is completed.
The extrusion operation by 1b is performed, the primary molded product X1 is extruded from the fixed die 4, and the extruded primary molded product X1 is transferred in parallel to the front surface position in the second forging station S2 by the material parallel transfer chuck. Will be done.

Next, at this second forging station S2, the primary molded product X1 is driven into the fixed mold 5 by the movable mold 12. As a result, the center portion of the primary molded product X1 is punched out by the fixing pin 5a to form the through hole c, and the burr b of the primary molded product X1 is fixed to the inner peripheral edge portion of the fixed mold 5 and the outside of the movable mold 12. The secondary molded product X2 is formed by punching with the peripheral portion.

Further, a burr punched out on the movable die 12 side.
Is removed from the movable die 12 by the stripper 5d as the movable die 12 moves backward, and falls downward. Further, the punching piece d punched into the movable die 12 by the fixed punch 5 a is discharged from the through hole 12 a of the movable die 12 to the discharge passage 12.
It is discharged to the outside via b.

After the movable die 12 is retracted, the extruding member 5b is pushed out to eject the secondary molded product X2 from the fixed die 12, and the ejected secondary molded product X2 is moved by the material transfer chuck. It is transferred in parallel to the front position in the third forging station S3.

Then, in the third forging station S3,
The secondary molded product X2 is driven into the fixed mold 6 by the movable mold 13. As a result, the outer shape of the rocker arm R having the outer shape of the movable die 13 and the fixed die 6 with high dimensional accuracy, the outer periphery of the intermediate portion in the thickness direction of the product portion a ′, and the through hole c thereof are provided. Tertiary molded product X with burrs b ', b "on the
3 is formed.

After the movable die 13 is retracted, the tertiary molded product X3 is ejected from the fixed mold 6 by the pushing operation of the extrusion pins 6b, 6b, and the ejected tertiary molded product X3 is a chuck device for material parallel transfer. Is transferred in parallel to the front position in the fourth forging station S4.

Then, at the fourth forging station S4,
The tertiary molded product X3 is driven into the fixed mold 7 by the movable mold 14. As a result, the burr b'formed on the outer periphery of the tertiary molded product X3 is punched out, and the burr b "in the central portion of the molded product X3 is also punched out by the punching fixed punch 7a, and the through hole c is formed in the central portion thereof. A rocker arm R is formed as a final molded product having a high dimensional accuracy in which ′ is formed.

Thereafter, the molded rocker arm R is
As the movable mold 14 moves backward, the pushing member 7b is pushed out to be discharged from the fixed mold 7 and, for example, is gripped by a take-out chuck (not shown) and taken out to a predetermined position.

As described above, the outer peripheral surface of the metal wire material X is previously subjected to the lubricating film forming treatment, and the metal wire material X having the lubricating film H formed on the outer peripheral surface thereof is used as the upper stage of the horizontal cold heading molding machine 1. Of the blank X'is fed to the vicinity of the forging station S1 of the blank X ', the cut blank X'is swung 90 degrees, and the lubricating coating H of the blank X'is at the upper stage. Since it was supplied so as to face each forging surface of the movable mold 11 and the fixed mold 4 in S1,
Lubricating film H facing each forging surface of the movable mold 11 and the fixed mold 4.
As a result, the coefficient of friction at the time of molding by the movable mold 11 and the fixed mold 4 is lowered to improve the workability, and it is possible to mold favorably without causing cracks. Further, according to the multi-stage horizontal cold heading and forming machine 1, due to the structure in which the movable dies 11 to 14 are moved on the horizontal plane, the load of the movable dies 11 to 14, the ram 8 and the like is moved during the movement. By supporting the movable dies 11 to 14 on the side, the load on the drive system for reciprocating the movable dies 11 to 14 in the horizontal direction can be suppressed, whereby the movable dies 11 to 14 can be horizontally reciprocated at a high speed. It is possible to speed up the forging forming at the forging station. This makes it possible to manufacture the rocker arm R from the metal wire material X at a higher speed by the multi-stage horizontal cold heading and forming machine 1.

A blank formed by cutting the material X is used as the metal wire material X, which has a rectangular cross section close to the shape of the cross section orthogonal to the longitudinal direction of the rocker arm R to be manufactured. The outer peripheral surface is supplied and transferred so that the opposed lubricating film forming surfaces on one side face the forging surfaces of the movable die and the fixed die in the upper forging station, respectively. The amount of plastic deformation at the time of molding by the mold can be reduced, and the molding can be further facilitated.

In the above-described embodiment, the metal wire material X having a rectangular cross section in a coil winding state in the lubricating film forming step.
Was immersed in a bath of lubricating liquid such as zinc phosphate to form a lubricating coating H on its outer peripheral surface.
The spraying device may be used to coat the outer peripheral surface of the metal wire material X, or the spraying device may be provided between the rotation support member 21 and the material supply device.

[0063]

As described above, according to the first aspect of the present invention, the lubricating coating layer is formed on the outer peripheral surface of the metal wire material, and the metal wire material is provided near the forging station in the upper stage of the cold forging machine. To the predetermined position, the blank is cut into a predetermined size, and the cut blanks face the forging surfaces of the movable die and the fixed die at the forging stations, respectively. Since the metal wire material having the lubricating coating layer formed on the outer peripheral surface thereof is cut to a predetermined size, the blank is formed by cutting the material into the blanks. The cold forging machine can be continuously and quickly supplied so as to face the forging surface, and the workability thereof can be improved. In addition, in each forging station, since the lubricating film forming surface of the blank is to be forged while facing the forging surface of the movable die and fixed die of each forging station, the movable die and the fixed die are formed. It is possible to reduce the friction coefficient at the time of molding by using, thereby improving the workability even under cold conditions and forging the rocker arm with high precision without cracking. It becomes possible.

Further, according to the second aspect of the invention, a cold forging machine having a plurality of forging stations horizontally arranged in parallel is used, and an outer peripheral surface is provided near the upper forging station of the forging machine. The metal wire material on which the lubricating coating layer is formed is supplied horizontally and orthogonally to the direction in which the forging stations are arranged in parallel, and then the material is cut into a predetermined size at this supply position, The blank cut into the dimensions is rotated 90 degrees so as to be orthogonal to the above-mentioned material supply direction, and the blank is formed so that its lubricating film formation surface faces the forging surfaces of the movable die and the fixed die in the forging station at the upper stage, respectively. Therefore, in the multi-stage horizontal cold forging machine, the structure is such that each movable die is moved on a horizontal plane, so that when moving it, By supporting the load of each movable die and ram on the machine base side, it is possible to suppress the load burden on the drive system for horizontally reciprocating each movable die, which allows the movable die to move horizontally at high speed. It is possible to reciprocally move to and rapidly perform forging forming at each forging station.
Moreover, it is possible to arrange a wire rod supply mechanism for supplying the above-mentioned metal wire material to the upper-stage forging station along the side of the upper-stage forging station with a small space. It is possible to suppress the conversion.

Further, according to the third invention, as the metal wire material, a metal wire material having a rectangular cross section that is similar to the shape of the cross section orthogonal to the longitudinal direction of the rocker arm to be manufactured is used, and the metal wire material has a predetermined size. The blank formed by cutting is forged at the forging station with the outer peripheral surface of one side facing the opposite lubricating film forming surface facing the forging surface of the movable die and the stationary die at the forging station at the upper stage. Since the molding is performed, it is possible to reduce the deformation amount of the blank at the time of forging and to reduce the load at the time of molding.

[Brief description of drawings]

FIG. 1 is a plan view of a blank obtained by cutting a metal wire material used in a method for manufacturing a rocker arm according to the present invention into a predetermined length.

FIG. 2 is a front view of the blank.

FIG. 3 is a plan view of a primary molded product that is press-molded by the rocker arm manufacturing method according to the present invention.

FIG. 4 is a front view of the same molded article.

FIG. 5 is a plan view of a secondary molded product that has been press-molded by the rocker arm manufacturing method according to the present invention.

FIG. 6 is a front view of the same secondary molded product.

FIG. 7 is a plan view of a tertiary molded product that is press-molded by the rocker arm manufacturing method according to the present invention.

FIG. 8 is a front view of the tertiary molded product.

FIG. 9 is a plan view of a rocker arm press-molded by the rocker arm manufacturing method according to the present invention.

FIG. 10 is a front view of the rocker arm.

FIG. 11 is a schematic perspective view of a multi-stage horizontal cold heading machine for heading a rocker arm.

FIG. 12 is a partially omitted sectional view of the same pressure molding machine.

FIG. 13 is a front view of the material swivel supply device as viewed from the side of FIG.

FIG. 14 is a cutaway plan view of the same portion.

FIG. 15 is an explanatory diagram showing a state of gripping a blank by the chuck device.

FIG. 16: First in a multi-stage horizontal cold heading machine
It is a partially expanded transverse cross-sectional view of a forging station.

FIG. 17 is a partially enlarged cross-sectional view of a second forging station in the same forging machine.

FIG. 18 is a partially enlarged transverse sectional view of a third forging station in the same forging machine.

FIG. 19 is a partially enlarged cross-sectional view of a fourth forging station in the same forging machine.

[Explanation of symbols]

1 Multi-stage horizontal cold heading machine 4-7 fixed type 11-14 Movable type H lubrication film R rocker arm X metal wire material X'blank S1 First forging station S2 Second forging station S3 Third Forging Station S4 Fourth Forging Station

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 64-5638 (JP, A) JP-A 1-152280 (JP, A) JP-A 62-187537 (JP, A) JP-A 60- 177185 (JP, A) JP 4-126561 (JP, A) JP 61-67771 (JP, A) JP 63-207441 (JP, A) JP 8-206771 (JP, A) JP-A-3-297531 (JP, A) Actual development 3-85140 (JP, U) Actual development 5-9734 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00

Claims (3)

(57) [Claims] 1. A method for manufacturing a rocker arm having a flat shape and a relatively elongated shape as a whole, wherein a metal wire material is used, and a lubricating liquid for reducing the friction coefficient at the time of forging is formed on the outer peripheral surface of the material. A lubricant coating layer is formed by adhering the material, and then the material is placed in the vicinity of the upper forging station in a cold forging machine, which is formed by arranging a plurality of forging stations each having a movable die and a fixed die. Supply, cut the material to a predetermined size at the supply position, and then cut the cut blank into a movable die and a fixed die in the forging station with the lubricating film forming surface in the upper stage. To the forging station so that they face each other, and then the blank formed by forging at the forging station is used as an intermediate molded product. It is characterized in that it is sequentially transferred to each forging station on the lower stage side so as to face each forging surface of the movable die and the stationary die of the stationary die, and at each of these forging stations, forging is performed stepwise into a rocker arm shape. Rocker arm manufacturing method. 2. A cold forging machine in which a plurality of stages of forging stations are horizontally arranged so that respective movable dies move on a horizontal plane, and a metal wire material is provided in the vicinity of the upper forging station. Supply in a horizontal direction and in a direction orthogonal to the direction in which the forging stations are arranged in parallel, and at the supply position, the longitudinal direction of the blank formed by cutting the material into predetermined dimensions,
By rotating 90 degrees so as to be orthogonal to the material supply direction, the lubricating film forming surface of the blank is made to face the forging surfaces of the movable die and the fixed die in the forging station at the upper stage, respectively. Item 2. A method for manufacturing a rocker arm according to Item 1. 3. A metal wire material having a rectangular cross section that is similar to the shape of the cross section orthogonal to the longitudinal direction of the rocker arm to be manufactured is used, and the material is cut into a predetermined size. The blank is supplied to the forging station so that the lubricating film forming surfaces on one side opposite to each other on the outer peripheral surface thereof face the forging surfaces of the movable die and the fixed die in the upper forging station, respectively. The method for manufacturing a rocker arm according to claim 1 or 2.